How common are MMC at 12 weeks?

[Charl881]

I’m 11 weeks pregnant on Tuesday and starting to get seriously anxious about my 12 week scan. I’m just so convinced that I will have had a missed miscarriage. I have lots of symptoms but I’ve heard that you can have a MMC and still be getting symptoms. Really wishing I’d booked a private scan now but now point as only just over a week to go until the NHS one.

I feel the exact same as you. Also 11 weeks. And have over a week to wait for the NHS scan. I have had a missed miscarriage before (diagnosed earlier than 12 weeks due to bleeding) and have had two healthy babies since then too. The fear is always there. I think it’s normal to be anxious and that the surging hormones don’t help!! Wishing you well for your scan 🙂

I've got 2 weeks until my 12wk scan.

Here is my very back of envelope calculation.

I've not read many people with MMC at 12wks where the embryo stopped developing before 6 weeks. MC risk drops by week, so if we take MC risk at 6wks to be the highest risk point, then it's about 16% risk. But it's much more likely that you would have MC'd naturally in the meantime. I found a stay that about 5% of pregnancies end inMC. Since about 25% overall end in MC this suggests about 1 in 5 MCs are missed. However it would be less usual for your body to still holding onto it by 12 weeks so let's say about 1 in 10 MCs at 6w will still be missed at 12wks, that would make it about 1.5% risk. And by 11wks your miscarriage risk is about 2% but it would have had less time to start on its own so say 0.5% chance of MC at 11wks being picked up at 12wks. So I think the likelihood is probably somewhere between 0.5% and 1.5%? I've also seen people give the odds of MMC being picked up at 12wk scan as about 1%, but I don't know where that comes from.

As you can tell, this has also been on my mind. 😩 Wishing you a calm week and a happy scan!

That should say, "I found a site saying that about 5% of pregnancies end in MMC."

I’m pregnant again after a miscarriage in July, 12 weeks. Got my scan in a couple of days and suddenly it seems forever to wait and my anxiety is through the roof about the scan picking up a MMC. I’ve also had lots of symptoms but regretting not having an early scan too. I think it’s very natural to feel anxious as the first scan approaches as I can remember feeling like this with my two other children. I‘m just trying to distract myself and stay away from
google.. Good luck for your scan next week!

@Melusina123 That’s a really interesting calculation and exactly what I’d been wondering although too lazy to work it out myself. Although I know that absolutely nothing can change what will happen, there is some comfort in knowing the stats.

@DottyLittleRainbow Sorry to hear about your mc and fingers crossed for your scan! I remember feeling the same with my DS but I had had an early scan with him so I think that helped a bit with hindsight.

@Highlandmama Let’s hope this week passes quickly for both of us!!

Totally get the worry @Charl881, I was terrified before my 12 week scan even though had one at 10 weeks for NIPT. From everything I read MMCs are way less common than MCs with bleeding/pain, and the sonographers I asked said that only around 3-5% of 12w scans are bad news. That’s a small number! I kept reminding myself that stats are overwhelmingly(!!) on my side even after 2 previous miscarriages. I am now getting nervous before my 20w scan next week - think it’s only normal. Fingers crossed for you x